Result of IOFIX (Intra Osseous FIXation) device for first metatarsophalangeal joint arthrodesis: A single surgeon's...

Arthrodesis of the first metatarsophalangeal joint (MTPJ) is a common procedure to treat significant first MTPJ arthritis. However, dorsal plates used for this have been associated with high incidence of metalwork removal. The IOFIX (Intra-Osseous FIXation) is a fixed angle device that is noted to provide a more uniform compression over a larger aspect of the fusion surfaces than a screw construct alone with the advantage of minimizing soft tissue irritation which can reduce the need for subsequent implant removal.

Twenty one consecutive patients who underwent primary first MTPJ fusion with the IOFIX were reviewed. The mean age of the cohort was 63 years (range 47-81), with 80% female. The ratio of left to right was 9:12. The mean follow up of was 28 months (range 13.4-48.2 months). Outcomes analyzed were rate of fusion, Manchester-Oxford foot questionnaire (MOXFQ) score, patient satisfaction, improvement in the intermetatarsal angle and complications.

Complete fusion of the first MTPJ was achieved in twenty (95%) patients. One patient had a non union and another patient developed a delayed union. The mean preoperative MOXFQ score improved from 49.7 (95% confidence interval: 46-52) to 17.9 (95% confidence interval: 12-22), p<0.05.Improvement gained in all the domains of the MOXFQ score (walking/standing, pain and social) was statistically significant (p<0.05). Eighteen out of 21 patients (85%) were very pleased or fairly pleased with the procedure.

Early results show that the rate of fusion achieved by using the IOFIX device for the first MTPJ arthrodesis in our series was found to be comparable to other devices quoted in the literature.